Tube cleaner



March 14, 1939. .1, McDERM ET ET AL I 2,150,306

TUBE CLEANER Filed Feb. 4, 1956 .23 J fl 8 l I V 7 .912 6 I I \M, va/41v l l I I l Patented Mar. 14, 1939 UNITED STATES PATENT OFFICE TUBE CLEANER Application February 4, 1936, Serial No. 62,280

8 Claims.

Our invention relates to that class of centrifugal cleaner heads for cleaning. out scale, coke and other accretions from tubes wherein the speed of rotation of the head acts. upon freely movable centrifugal arms or pins moving in longitudinal planes.

One object of the invention is to provide a cleaner head of this type wherein the tendency to self-feed varies with the amount of outward movement of the pins. Another object is to so arrange the parts that the outward swinging movement tends to move the cutters along the pins in one direction, while the varying selffeeding angle tends to move them in the opposite direction along the. pin, so that these tendencies are opposed; thus reducing the wear upon one or both of the heads of the spider carrying the parts.

Another object is to provide a head which will so automatically tend to stay in a certain position longitudinally of the tube until it should be moved, and when it should be moved it then tends to advance or self-feed itself. In. other words, our improved head tends to cease feeding when further cleaning is needed at the place where it is working. and to advance when its duty is finished at that zone of the tube, due to an increasing self-feed angle. Furthermore, when our improved head is working under light duty, that is when little or no accretion is being removed, under the high speed the centrifugal element predominates and the self-feed angle tends to increase. If, on the other hand, a large amount of work is being donein removing scale, the motor will slow down, its torque will increase, the centrifugal force will diminish, the self-feed decreases and the head tends to remain in one position until the motor on building up speed tends to feed the head onward.

Another object of the invention is to provide a simple, easily assembled and disassembled, and strong sturdy construction embodying these features.

In the drawing:

Figure l is a side elevation, partly in section, showing one form of our invention;

Figure 2 is a rear elevation with the rear locking head removed, two of the three pins: being shown in cross section and having a modified front guide construction;

Figure 3 is a front elevation; an

Figure 4 is a detail view of the spider and one of the pins with cutters illustrating the various angles of self-feed.

In the drawing, we show a supporting frame or head consisting of a spider having an integral front head 2, integral rear head 3 and integral connecting arms 4 which are shown as three in number. In the form illustrated, we show three 60: swinging pins 5, whose front ends pass through holes 6 in the front head and through non-radial slots 7 in the rear integral head. The slots in the rear head are narrower than the diameter of the pins and the pins are cut away to form fiat surfaces 8, where they move within the slots.

These flat surfaces are, of course, somewhat longer than the thickness of the rear integral head. The slots I extend outwardly to the periphery of the rear head at acute angles to radial planes, through their inner end, and the rearwardly projecting generally cylindrical. ends of the pins, which are somewhat chamfered or rounded off, move within the enclosed non-radial slots 9 of a rear head lock plate Iii, which is inwardly recessed to form a circumferential flange H, closing the open ends of the slots 1 in the integral head when the lock is in place.

The lock plate is secured in place by a. looking member consisting of a screw bolt I2, which screws into a central screw threaded hole in the rear integral head of the spider, the hexagonal head of the screw bolt butting against the central portion of the lock plate. This lock bolt has an internally threaded central hole In to receive a corresponding externally threaded extension of the drive shaft of a motor.

The slots in the rear locking plate and the open ended slots in the rear head of the spider are non-radial and extend outwardly farther and farther away from radial planes at their bases. The slots in the lock head I!) are. slightly larger than those in. the rear head 3 which form the rear guides for the chamfered portions of the pins.

In the form shown, the pins do not rotate, but move under the action of centrifugal force, thus acting upon the scale through the medium of the rotary cutter wheels l3, of which the teeth in the front one are preferably tapered in. a general conical shape. In order to efiectively utilize centrifugal force of rotation, the guide slots in head 3" preferably extend positively or in the direction of rotation of the head, see Figure 2. Self-feeding action is accomplished by mounting the axes of the pins 5 askew with respect to a plane taken through a longitudinal axis of the head. As shown in the drawing, the guide slots in the front and rear portions of the head are, in the construction of Figure 3, askew with respect to each other;

The holes in the front head 2 which contain the front ends of the swinging pins are chamfered from both ends sufficiently to not only allow proper swinging of the pins, but also to allow the pins to be removed when the rear locking plate 10- is taken off. The rear locking plate has an internal hole 14, which fits over the dowel pin [5 driven into and projecting from the rear integral head 3 of the spider, thus properly placing or locating the rear locking plate, when its slots register with those in the rear head. The

arrangement of the rear guide slots at an angle to radial planes is important in producing the advantages and functions above referred to. For example, in Figure 4, the line H indicates a plane through the axis of the spider, while bb indicates the departure from this axis in a minimum or near minimum position of the pin in its movement, and the line c--c indicates the. maximum position of the pin, these variations being about 2 and 4 respectively relative to the axial plane, in the form shown. .It will be noted that the slots'or guides for the pins which support the cutter elements incline. or diverge out-' wardly or away from or at angles to planes extending radially and longitudinally through inner 'Hence, the. diameter of the, free space is here ends of the slots or guides In other words, the guides diverge outwardly from radial planes containing the longitudinal axis of the'head'. This permits the necessary free centrifugal action of" the cutter elements whereby an automatically controlled self feeding action is accomplished.

'In use, the front end of the head which is of the smallest diameter, of course, continuously meets the maximum depth of scale or deposits.

the smallest and as the deposit is cleaned out, the bare tube is finally encountered at the rear portion of the head. The head is, of course, provided with at least enough travel to clean out the deposit and come in contact by its cutter surfaces with the actual tube surface. Hence, the coke is cleaned out by the cutters which advance on a conical surface, the working surface being the interior of the envelope of a frustrum of a cone. This is, of course, the reason for making the tapered head since it not only has the ability -to enter smaller holes, but also because its shape corresponds generally to the, surface of the deposit upon which it exerts its cutting action. As the angle of the cone changes, the self-feed angle changes. If the cutting head were forced into the deposit in I such a way that it worked upon a cylindrical surface due to the extreme depth of the coke at the back end, it would obviously have no self-feed and none would be required. Hence, the taper at which the pins work is a measure of the amount of deposit to be removed.

In using such a head, the important features are the angle of taper of the pins and the angles of inclination of the 'g'uide'slots which control the self-feeding tendency of the head. In operation, each pin has a compound'movement, namely, the outward swing and the sidewise angular movement. The axial angularity of the pin will, of course, be greatest when the pin is at its outermost swing. As the angle of taper of the pins increases, the angle of self-feed also increases on account of the outward divergence of the slots from axial planes. 7

The angularity of the slots is. positive in the direction of rotation of the head, and the self-feed angle is very small with the pin at the inner end of its throw and large when at its maximum throw. Hence, when the head is forced into an accreted tube, the self-feeding tendency is small and the heads tends to stay in the same place,

- but as the cleaning proceeds in the zone being treated, the throw of the pins increases and the tendency to self-feed increases, so that when the cleaning operation is'completed the feed angle has been increased to a point which will cause the head to tend to move forward.

While the head, of course, requires guiding and movement by the operator, nevertheless when it I .in advancing it. These angles may be so proportioned that for a certain condition of scale or coke thickness and structure, the movements would be automatic, or they might be increased so that the operator instead of pushing. would need to hold the head back. In the movements'of the pins, their angularity tothe axis is continu-,

ously varying both in the plane of the axis and in a plane angularto such a plane.

The relationship between the guide slots of the front and back portions of the head is such that the cleaner support pins will increasingly diverge when they move outwardly with respect to. the longitudinal axis of the head. It will thus appear that the slots in the back portion of the head diverge differentlythan the slots in the front portion thereof (see Figures 2 and 3), in order that increasing divergence of theax'es of the pins,

may be attained, and in order that the variable self-feeding action will automatically increase with the increasing divergence of the axes of the pins.

As the cutters rotate on the pins, their teeth engage the coke or scale with a continually. in-' creasing tendency to pull the head forward. as they clean. Due to this tendency, the cutters move forward on the pins and tend to come in contact with the front end of the spider and wear it. This tendency will, of course, vary with the self-feed angle. On the other hand, due to the angle of taper, the cutters tend to .move backward on the pin and wear out the rear end of the spider,'under centrifugal force created in rotation.

Hence, in our improved head there are opposed tendencies on thecutters tending to move them along the pins, thus creating more or less of a balance which minimizes wear on the spider.

The balance against forward and backward movement is maintained simultaneously with the forward pull on the spider which causes the selffeed. The-self-feed results from the tendency,

' parallel, the cutters would merely ride up against the front portion of the spider and exert their pull directly on the spider itself.

The advantages of our invention will be apparent to those skilled in the art from the above description and from the operation of the head.

The pinholes in the front head may be ofa rough ball and socket type as shown, or they may be mounted in such head in any manner to allow the properswinging as directed by the rear slots. On the other hand, the swing may be from the rear head, the angular slots being-in the front head, and likewise inclined to axial planes, like as V those shown in the rear head. Furthermore, the

head is of a' very sturdy, simple type, easily as- The conical shape may be varied in degree or kind and other changes may be madewithout departing from the spirit of our invention or scope of our broader claims. 1

We claim:

1. A rotary cleaner head havingla longitudinal axis and guides, at least some of said guides in-v clining outwardly from radial planes containing the longitudinal axis of the head and outwardly in the direction of rotation of the head, pins outwardly-movably mounted in said guides, said guides being arranged to movably mount said pins in such a manner that the axes of said pins are askew with respect to a plane through the longitudinal axis of the head when said pins move outwardly in said guides, and cleaner elements operably mounted on said pins, said guides inclining outwardly in such a manner that longitudinal axes of said pins increasingly diverge with respect to the plane through the longitudinal axis of the head as said pins move outwardly in said guides and that the pins will move outwardly with respect to the head under centrifugal force set up by rotation of the head.

2. In a rotary cleaner head having a longitudinal axis, pins operably mounted in said head, rotatable cleaner elements on said pins, said elements being free to move outwardly under centrifugal force and to move inwardly under force exerted by the work when the head is rotating in a desired direction, and means associated with said head to guide said cleaner elements in their above-mentioned outward and inward movements, said guide means being constructed and arranged to direct said cleaner elements in their inward and outward movement in such a manner that axes of said cleaner elements will increasingly diverge in their outward movement from a radial plane containing the longitudinal axis of the head and as to provide a variable self -feed controlled by said above-mentioned forces.

3. A rotary cleaner head having guides extending outwardly in the direction of rotation of the head, pins outwardly-movably mounted in said guides with their longitudinal axes inclining outwardly-backwardly of the head, said pins being divergent with respect to a plane through the longitudinal axis of the head at least when moved outwardly in said guides, and cleaner elements operably mounted on said pins, said cleaner elements being constructed and operably arranged to provide a force component with a surface being cleaned that tends to move the head longitudinally, said cleaner elements also being constructed and operably arranged to provide an increase of such force component as said pins move outwardly in said guides, said cleaner elements being free to move at least a short distance longitudinally of said pins, so that there will be an automatic balancing of backward thrust forces produced by the cleaning action of said elements and of the forward thrust forces produced by the tractive eifect of said elements tending to move the head longitudinally.

4. A rotary cleaner head having a longitudinal axis and suitable guides, longitudinally-extending cleaner pins mounted for inward and outward movement under centrifugal force in said guides, cleaner elements operably mounted on said pins, at least some of said guides extending outwardly in the direction of rotation of the head in such a manner that the longitudinal axes of said pins increasingly diverge from a plane of the longitudinal axis of the head as said pins move outwardly along said guides.

5. A rotary cleaner head of general frustroconical shape having cleaner element support guiding slots therein, said slots extending outwardly in the direction of rotation of the head in at least one end of the head, said extending slots diverging outwardly from radial planes containing the longitudinal axis of the head, longitudinally-extending cleaner supporting elements operably mounted in said slots to move outwardly therealong under centrifugal force, said slots being of such a form and direction that the longitudinal axes of said cleaner element supports will increasingly diverge with respect to planes through the longitudinal axis of the head when said cleaner element supports move outwardly in said slots.

6. In a rotary cleaner head having front and back head portions, longitudinally-extending pins, guides associated with said front and back head portions, said pins being operably mounted within said guides, the guides in one of said head portions diverging outwardly from radial planes containing the longitudinal axis of the head and in the direction of rotation of the head, cleaner elements operably mounted on said pins, said pins being movable outwardly along said divergent guides under centrifugal force, said divergent guides diverging in such a manner with respect to the guides in the other of said head portions that the longitudinal axes of said pins will divergewith respect to a. plane through the longitudinal axis of the head when said pins move outwardly in said guides, and such that the angle of divergence of said longitudinal axes will increase as said pins move outwardly.

'7. In a rotary cleaner head having spaced-apart front and back head portions, longitudinally ex-' tending pins, cleaner elements operably mounted on saidpins, guides in said front head and said back head portions operably mounting said pins, said guides in said head portion diverging outwardly from radial planes containing the longitudinal axis of the head, said guides in at least one of said head portions extending outwardly in the direction of rotation of the head, the guides. in said front head portion having a different angle of divergence than the: guides in said :back head portion, the divergence of the guides in said front and back head portions being such that the 1ongitudinal axes of said pins will diverge and increase in divergence with respect to planes through the longitudinal axis of the head when said pins move outwardly.

8. In a rotary cleaner head having spaced-apart front and back head portions, longitudinally extending pins, cleaner elements operably mounted on said pins, guides in said front head and said back head portions operably mounting said pins, guides in one head portion diverging outwardly from radial planes containing the longitudinal axis of the head, the guides in said front head portion having a different angle of divergence than the guides in said back head portion, the divergence of the guides in said front and back head portions being such that the longitudinal axes of said pins will increase in divergence with respect to planes through the longitudinal axis of the head when said pins move outwardly in said guides due to centrifugal force, said cleaner elements being free to move longitudinally on said pins, so that a forward thrust action produced by a self-feed action of said cleaner elements will be offset by a rearward thrust action produced by a cleaning action of said elements.

JOHN R. McDERMET.

PAUL T. KEEBLER. 

